1. Field of the Invention
The present invention relates generally to a portable communication device such as a portable terminal and a Personal Digital Assistant (PDA). More particularly, the present invention relates to a microphone rubber apparatus mounted on a Surface Mounted Device (SMD) microphone prepared on a printed circuit board to protect the SMD microphone from an external physical impact and the like.
2. Description of the Related Art
A portable communication device, including a portable terminal, an MP3 player, a Personal Media Player (PMP) and a PDA, is a device with which a user can access a variety of contents while carrying it with him or her.
The portable communication device has a tendency toward multifunction and miniaturization in line with consumer demands.
Normally, a microphone is installed in the portable communication device such as the portable terminal and the PDA to conduct transmission of speech during a call. To mount the microphone on a printed circuit board, a microphone lead is formed on a lower end of the microphone and soldered onto the printed circuit board. However, the heat delivered to the printed circuit board during the soldering may deform a Polyethylene Terephthalate (PET) film, which is a vibration film, in the microphone, deteriorating a characteristic of the microphone.
Recently, circuits for ensuring a frequency characteristic of a microphone mounted in the portable communication device and cutting off electrostatics from the exterior are formed by an SMD technique, thereby removing a need for separate works and improving work efficiency for microphone installation. In this technique, all sorts of circuits for controlling and/or protecting a basic characteristic of the microphone are formed in one body, increasing space efficiency during forming of peripheral circuits of the microphone. Such an SMD microphone is easy to install and can prevent an echo phenomenon and a decrease in radiation performance, which may occur while the microphone is soldered onto the printed circuit board.
A microphone rubber is mounted on the SMD microphone to protect the microphone from an external impact or the like and prevent the echo phenomenon. The microphone rubber may remarkably reduce a possible breakaway of the microphone even though an external force such as an impact is applied to the portable communication device.
However, since a structure of this microphone is exposed to an inner side of a terminal, capability of the microphone may be affected by noise, heat, sound and the like inside the portable communication device, causing a decrease in transmission sensitivity.
In addition, a groove having a tolerance slightly less than a size of the microphone is formed in the microphone rubber so that the microphone rubber may wrap up the microphone. Thus, the microphone can be fit into the groove. However, when a user drops the terminal by mistake or applies an impact thereto, the microphone rubber may be separated from the microphone.
Though the microphone rubber closely adheres to the SMD microphone, the microphone may occasionally be detached from the microphone rubber during a distribution test. To address this problem, use of the SMD microphone is prohibited during the distribution test or soldering points of the microphone are added, but this may lead to the cost increase and production delay. Further, the microphone may be deformed or out of order due to an impact applied thereto while the microphone rubber is separated from the microphone.
Accordingly, there is a long-felt need for a microphone rubber apparatus for a portable communication device, capable of preventing a microphone rubber from being detached from a microphone due to an external impact applied to the portable communication device, and of easing or absorbing the impact. Also, there is a need for a microphone rubber that exerts no influence on an SMD microphone during the distribution test.